If necessity is the mother of invention, we should be very afraid. Among the recently granted US patents is an invention to contain suicide bombers, technology that prevents you from getting shot, and a way to rest in peace.

Here are a few of the many new ways to protect ourselves in the violent world:More realistic kills

This technology seeks to make combat exercises more graphic and lifelike, to provide better training. During combat exercises, when a soldier hits the enemy with infrared "bullets," sensors on the target's vest and helmet will trigger the discharge of plumes of dust to imitate someone getting shot by actual rounds.

The human target could wear "sensors and discharge members at his right and left shoulders, right and left hips, chest, various positions on his back, and multiple positions on his helmet."

Out of sight

Hunters can become the hunted in areas where visibility is poor.This patent uses a radio frequency interrogator mounted to the firearm and a transponder that's attached to the hunter's jacket.

When the hunter's rifle is aimed at a person wearing the transponder, the system would emit a signal to warn the shooter.

Wrap him up

Trying to disable or kill a suicide bomber may cause detonation of the explosives. This patent is for a blast shield that's initially contained in a canister and shot at the bomber.

Once fired, weights attached to the perimeter of the shield would act as bolas that wrap around the suspect, according to the patent filing. Strong synthetic fabrics in the shield would absorb heat and shock waves from an explosion, and resist penetration by projectiles.

iCan fight back

It's another sign of the scary times: Protective cases now in the market can turn your mobile phone into a stungun or pepper spray dispenser. This patent tries to stuff even more self-defence features into your phone, including the ability to spray a stench, foaming agent or dye for identifying an attacker.

It also incorporates a panic button that utilises the phone's camera to capture images and audio of the assailant, and then automatically sends those files to law enforcement along with location information and a time stamp. Packing at home

The inventor behind US Patent No 8,430,461 wants you to rest easier. Among the many ways you can covertly store firearms at home — in a bed's headboard, desk globe or the side of a mattress — this furniture design aims to give you quicker access to the gun in your nightstand and elsewhere.

Features include a latched drawer with spring action that quickly ejects, and an "arm-accepting cut-out" on the side of the drawer so a person can discreetly and more easily grab a gun while lying in bed.